Automatic deicer for electrical transmission lines



J. H. POTTER Dec. 8, 1953 AUTOMATIC DEICER FOR ELECTRICAL TRANSMISSION LINES 2 Sheets-Sheet 1 Filed May 15, 1955 FIG. a.

F'/ G. .L.

INVENTOR. J HN f-I. POTTER,

.wm/wm ATTOENEYS.

J. H. POTTER Dec. 8, 1953 AUTOMATIC DEICER FOR ELECTRICAL TRANSMISSION LINES 2 SheetsSheet 2 Filed May 15, 1955 IILIUM IMQI INVENTOR.

uomv H. perv-EB,

Mamau fimmv-flmm ATTORNEYS.

Patented Dec. 8, 1953 UNITED STATES PATENT OFFICE AUTOMATIC DEICER FOR ELECTRICAL TRANSMISSION LINES This invention relates to transmission lines, and more particularly to means for automatically detecting the accumulation of ice on electrical transmission lines and effecting the removal thereof.

A main object of the invention is to provide a novel and improved apparatus for use on electrical transmission lines for detecting and removing accumulations of ice therefrom, the improved apparatus being simple in construction, being easy to install, and requiring no external source of power.

A further object of the invention is to provide an improved de-icing apparatus for use on electrical transmission lines for automatically detecting and removing accumulations of ice from the lines, whereby the lines are protected against breakage due to the weight of accumulated ice thereon, the improved apparatus involving inexpensive components, being reliable in operation, and being rugged in construction.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a top view of an improved switch de.. vice employed in one form of automatic ice detecting and removing apparatus for transmission lines in accordance with the present invention.

Figure 2 is a vertical cross sectional view taken on the line 2--2 of Figure 1.

Figure 3 is a horizontal cross sectional view taken on the line 3--3 of Figure 2.

Figure 4 is a fragmentary perspective view showing a pair of transmission lines supported on a pole and provided with improved ice-detecting and removing means according to the present invention and including a switch device such as that illustrated in Figures 1, 2 and 3.

Figure 5 is a top plan view of a modified form of ice-detecting switch device which may be employed in a transmission line de-icer according to the present invention.

Figure 6 is a vertical cross sectional view taken on the line 6-6 of Figure 5.

Figure 7 is a rear end elevational view of the switch device shown in Figures 5 and 6.

Figure 8 is a vertical transverse cross sectional view taken on the line 8-8 of Figure 6.

Figure 9 is a front end elevational view of the switch device illustrated in Figures 5 to 8.

Referring to the drawings, and more particularly to Figures 1 to 4, II and I2 designate a pair of transmission lines which are supported by means of insulators I3 and I4 on the cross arm 4 Claims. (Cl. 219-20) I5, said cross arm being secured to the pole I5 in the usual manner. Mounted on the top end of the pole I6 is an ice-detecting switch device, designated generally at H.

The switch device II comprises a switch housing I8, which may, for example, be of square or rectangular horizontal cross section, as illustrated, which is rigidly secured to a base member I 9, the base member I9, being in turn secured to the top end of the pole I6, as shown in Figure 2. The base member I9 is formed with a central recess 20 which slidably receives the lower end of a vertical, square rod member 2 I. Integrally formed with the top end of the rod member 2| is the cover member 22, said cover member being provided with the depending marginal flange 23 extending outwardly adjacent the rim 24 of the housing I3, as shown in Figure 2. The cover member 22 is biased upwardly by a plurality of coiled springs 25 connecting the rod 2| to the inside surface of housing I8, in the manner shown in Figure 2, whereby the springs 25 urge the cover member 22 and the rod 2| to the elevated position thereof illustrated in Figure 2.

Secured on the reduced lower portion 10 of the rod 2| is a sleeve II carrying the conductive band 21, the sleeve member 'II being of insulating material. Secured on the base member I9 sur.. rounding the recess 28 is the flat insulating ring 28, and mounted on the ring 28 are the respective spring contacts 29 and 30 which engage opposite sides of the rod member 2|, as shown in Figure 2. In the normal position of the top cover 22, the spring contacts 29 and 30 engage the insulating sleeve below the conductive band 21. However, when the cover 22 is depressed, as by the acciunulation of a predetermined amount of ice on its top surface, the rod member 2| is moved downwardly and the band 21 conductively engages the spring contacts 29 and 30, closing said contacts.

Designated at 3| is a connecting wire which connects the spring contact '29 with the transmission line conductor I I. The connection of the wire 3| to the transmission line conductor II is shown at 34. Connected to the opposing spring contact 3'0 is the heating wire 32, said heating wire being helically wrapped around the transmission line conductor II, as shown at 35, said heating wire being provided with a suitable heat transmitting, electrically insulating coating, to enable heat to be readily transmitted therefrom to the transmission line conductor I I while at the same time electrically insulating the heating wire with respect to said transmission line wire.

The heating wire 32 extends for a substantial length along the transmission line conductor II and is then brought over to the other transmission line conductor l2 and is helically wound thereon, as shown at 36. The heating wire 32 is finally connected to the transmission line conductor |2 at 31, as shown in Figure 2. Thus, when the switch contacts 23 and 30 are electrically connected by the depression of the top cover member 22, the heating wire 32 is connected across the transmission lines by the bridging of the contacts 29 and 30, through the wire 3| which connects contact 29 to transmission line conductor i H Mounted in the top cover [2 subadjacent to the horizontal top wall thereof is a heating winding 38 having one terminal thereof connected by a wire 39 to the switch contact 30. The other terminal or" the heating winding 38 is connected by an insulated wire 33 to the transmission line conductor l2 and is connected to said transmission line conductor at 31, along with the heating wire 32. Thus, when the top cover 22 is depressed in response to the accumulation of a predetermined quantity of ice thereon, the heatingwinding 38 is energized along with the heater wire 32, whereby the ice which has accumulated on the top cover 22 is melted after a period of time, the said period of time being sufiicient to enable the heating Wire 32 to substantially clear the transmission line conductors i2 and II of the ice accumulated thereon. I

It will thus been seen that when a predetermined weight of ice accumulates on the top cover 22, the switch contacts 29 and 33 are bridged, causing the heating wire 32 and the heating Wire 38 to be simultaneously energized, and after a sufficient period of energization, namely, thetime required for the weight of ice on the cover 22 ,to be diminished suiiiciently to allow springs 25 to elevate band 21 out of engagement With the spring contacts 29 and 30, the heating action is discontinued. This generates .asuflicient amount of heat to maintain the transmission line conductors H and I2 surficiently clear of ice to prevent breakage of said conductors and to protect the transmission line against ice damage. At the same time, a relatively small amount of current is required to generate therequired amount of heat and thus the transmission lines II and I2 are substantiallyunafiected by the connection of the heating elements 38 and32 thereto.

As shown in Figure 3, the rod member 2| is preferably square or rectangular in cross section,

the recess 26 being of similar cross section, whereby any tendency of the shaftmember2l and the cover 22 to rotate is prevented. This prevents the springs 25 from being subjected to excessive strain, whereby the device is reliable in operation and requires a minimum amount of maintenance.

Referring now to the form of the invention iliustr'ated in Figures to 9, an alternative switch device is designated generallyatq5fl, said switch device comprising a substantially rectangular housing member 5| which may be secured on a suitable base plate, such as the plate |'9 employed in the previously described form of the invention. Designated at 53 is a toggle switch which is mounted in one wall of the housing 5| and which is provided with the outwardly projecting switch operating lever 54. Designated at 52 is the transversely extending horizontal pivot-shaft which extends rotatably through the side walls of the housing 5| adjacent the walloi the housing opposite to that on which the switch 53 is mounted. Designated at 55 is an arm which extends over the housing 5| and which is provided with the opposed depending side flanges 56, 56 through which the ends of shaft 52 extend and to which said shaft ends are secured, as shown at 58, suitable spacing sleeves 51, 51 being provided on the shaft between the flanges 56, 56 and the side walls of housing 5|. The arm 55 is provided with the depending rear flange element 58, said flange element having an aperture 59 through which the switch lever 54 extends, as shown in Figure 6, whereby rotation of the arm 55 clockwise, as viewed in Figure 6, causes the lever 54 to be rotated upwardly to switch-closing position. The arm 55 is biased counterclockwise, as viewed inFigure 6, by suitable springs 60, 66

connecting the upper portion of flange 56 to the adjacent side wall of housing 5|, springs 60 being arranged on opposite sides of the switch lever 54, as shown in Figure 5. i I a a One terminal of the switch 53 is connected by a wire 3| to the transmisison line conductor II, for example, at 34, as in the form of the invention shown in Figure 4.

The other terminal of the switch is connected to the heating wire '32, which is engaged around the line conductors H and i2 and which is connected to the line conductor I2 at 31, as shown in Figure 4.

Secured beneath the arm 55 is the heating winding 6| which has one terminal thereof connected by the wire 39 to the same switch contaet es that to which the wire 32 is connected. The other terminal of the heating winding 6| is connected by a wire 33 to the transmission line conductor i2 at 3'! in the manner illustrated in Figure 4.

In operation, when a predetermined weightjof ice accumulates on the arm 55, the weight of ice causes the arm to be rotated from the normal position thereof "shown in Figure 6 in a clockwise direction, as viewed in Figure 6, whereby the switch lever 54 is rotated upwardly to its closed position. This simultaneously connects the heating wire s: and the heating wire '3: across the transmission lines, whereby heat is generated in the. said heating wires. After 'a period of time sufficient to melt enough ice from that which has accumulated on the arm 55 'to allow said arm to beelevated by springs 66 a sufficient amount to open switch 53, the heating isdiscontinued. Thus, as in the previously described form of the invention, the switch device .is responsive to the accumulation of a predetermined weight of ice on the arm 55 to energize the heating elements GI and 32 and to maintain said elements energized through a time period suiiicient to reduce the weight on arm 55 so that said arm is moved upwardly to open switch 53. This heating period is suiiicient to substantially clear the accumulated ice from the transmission line conductors H and I2 and to prevent ice damage to said conductors.

The apparatus above described may be employed on other than power transmission lines, for example, on telephone or telegraph, lines, by providingsuitable independent sources of heating current, such as batteries or the like, on the poles I8, and by connecting the conductors 31 and 433, '36 to the respective opposite terminals of the batteries. In other words, separate sources "of heating current may be employed in placeof the transmission line c'onductors II and 12.

While certain specific embodiments of an improved automatic ice detecting and removing apparatus for electrical lines have been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is;

1. In a transmission line, a support, a pair of transmission line conductors on said support, a switch housing on said support, a weight-responsive flat top member overlying said switch housing, means movably connecting said top member to said housing, said top member being movable relative to said housing when a predetermined weight of ice collects thereon, electrical heating means in heat-transmitting relation to said top member and conductors, a normally open switch in said housing, means closing said switch responsive to movement of said top member, spring means biasing said top member toward switchopening position, and circuit means electrically connecting said heating means to said line conductors through said switch.

2. In a transmission line, a support, a pair of transmission line conductors on said support, a switch housing on said support, a weight-responsive, flat top member overlying said switch. housing, means movably connecting said top member to said housing, said top member being movable relative to said housing when a predetermined weight of ice collects thereon, electrical heating means in heat-transmitting relation to said top member and conductors, a normally open switch in said housing, means closing said switch responsive to movement of said top member, spring means biasing said top member toward switchopening position, and circuit means electrically connecting said heating means to said line conductors through said switch, said heating means comprising a heating winding mounted beneath and adjacent to said top member, and an insulated heating conductor electrically connected in parallel with said heating winding and wrapped around said line conductors.

3. In a transmission line, a support, a pair of transmission line conductors on said support, a switch housing on said support, a weight-responsive flat top member overlying said switch housing, means movably connecting said top member to said housing, said top member having a portion movable downwardly relative to said housing when a predetermined weight of ice collects thereon, spring means connecting said top member and said housing and biasing said movable portion upwardly, electrical heating means in heat-transmitting relation to said top member and conductors, a normally open switch in said housing, means closing said switch responsive to downward movement of said portion of the top member, and circuit means electrically connecting said heating means to said line conductors through said switch, said heating means comprising a heating winding mounted beneath and adiacent to said top member, and an insulated heating conductor electrically connected in parallel with said heating winding and wrapped around said line conductors.

4. In a transmission line, a support, a pair of transmission line condi ctors on said support, a switch housing on said support, a weight-responsive, flat top member overlying said switch housing, means movably connecting said top member to said housing, said top member having a portion movable downwardly relative to said housing when a predetermined weight of ice collects thereon, spring means connecting said top member and said housing and biasing said movable portion upwardly, electrical heating means in heattransmitting relation to said top member and conductors, a normally open switch in said housing, means closing said switch responsive to downward movement of said portion of the top member, said top member being provided with a protective depending peripheral flange extending below the top plane of said housing, and circuit means electrically connecting said heating means to said line conductors through said switch.

JOHN H. POTTER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 682,768 Taylor Sept. 17, 1901 743,331 Ries Nov. 3, 1903 1,863,626 Fischer June 21, 1932 1,917,205 Horle July 4, 1933 1,936,391 Harrower Nov. 21, 1933 2,159,186 Tyler May 23, 1939 2,613,295 Stone Oct. '7, 

